Spring forming apparatus

Abstract

A first large drive gear for slider driving mechanisms and a second large drive gear for a tool rotating driving mechanism are disposed coaxially with an axis of a wire feeding quill and in parallel with a rear surface of a front base frame panel, and a single small drive gear and a plurality of small driven gears corresponding to a plurality of wire working units are disposed around each of these large drive gears. A plurality of slider driving mechanisms and at least one tool rotating driving mechanism are operated with a single common servomotor respectively.

What is claimed is: 
     
       1. A spring forming apparatus comprising: a wire feeder unit including at least a pair of wire feeding rollers that feed wire into a wire working region through a quill, and   a plurality of separate wire working units to bend and cut the wire to obtain a spring,   wherein the plurality of wire working units are disposed radially around the axis of the quill, each of the wire working units has a slider assembly which moves perpendicularly between an advanced position and a retreated position with relation to the axis of the quill and which carries an elongate working tool which is held by a working tool holder as a portion of the slider assembly, the working tool and working tool holder of at least one of the wire working units being rotatable about a longitudinal axis of the elongate working tool, the working tool being engageable with the wire in the wire working region when the slider assembly is positioned at the advanced position and retreating from the wire working region when the slider assembly is positioned at the retreated position,   wherein the working tool holder of at least one of the wire working units is rotatable, with the working tool, around the longitudinal axis of the working tool, the longitudinal axis being perpendicular to the axis of the quill,   wherein the spring forming apparatus further comprises a wire feeding driving mechanism which drives the wire feeding rollers, a slider driving mechanism by which each of the slider assemblies is moved perpendicularly between the advanced position and the retreated position with relation to the axis of the quill, a tool rotating driving mechanism for rotating the working tool holder, with the working tool, around the longitudinal axis of the working tool, and a control device for operating the wire feeding driving mechanism, the slider driving mechanism and the tool rotating driving mechanism in a sequence determined by a form of the spring, and   wherein a volume of the wire fed through the quill, which includes a wire length or a wire supply speed, a moving volume of a front end of the slider assembly between the advanced position and the retreated position, which includes a feeding length and a feeding speed, and a rotating volume of at least one of the working tool holders, which includes a rotational angle and a rotational speed, are controlled by the control device, whereby the wire is subjected to bending and cutting operations by the plurality of the working tools held by the plurality of the working tool holders, respectively.   
     
     
       2. A spring forming apparatus according to claim 1, wherein: the plurality of slider driving mechanism comprises a driving motor for the slider assembly, a first common large gear which is driven by the driving motor for the slider assembly, a plurality of first small gears which are arranged circumferentially in engagement with the first large gear and correspond to the plurality of slider driving mechanism, respectively, and a plurality of movement turning mechanisms by which movements of the first small gears are turned into linear motions to move the slider assembly, respectively,   the driving motor for the slider assembly being able to be controlled in a rotational speed and a rotational angle.   
     
     
       3. A spring forming apparatus according to claim 1, wherein: at least one of the working tools comprises a wire bending tool which has a pair of projections on an end thereof facing a side of the wire fed through the quill,   the projections having a gap allowing the wire to pass through therebetween, whereby the wire positioned between the pair of projections is bent when the wire bending tool rotates around a longitudinal axis of the wire bending tool.   
     
     
       4. A spring forming apparatus according to claim 1, wherein: the working tools are detachably held by the working tool holder.   
     
     
       5. A spring forming apparatus according to claim 1, wherein: the working tool holders of at least two wire working units are designed to be driven to rotate together with the working tools around the longitudinal axes of the working tools, respectively,   the respective longitudinal axes being perpendicular to the axis of the quill.   
     
     
       6. A spring forming apparatus according to claim 1, wherein: at least two of the tool rotating driving mechanisms comprise a driving motor for rotating the tools, a common second large gear which is driven by the driving motor for rotating the tools, at least two second small gears which are arranged circumferentially and in engagement with the second large gear and correspond to the at least two tool rotating driving mechanisms, respectively, and at least two rotational movement axially turning mechanisms by which an axial direction of of each the rotational movement of the second small gears are turned to rotate the working tool holders and the working tools, respectively, and the driving motor for rotating the tools can be controlled in terms of a rotational speed and a rotational angle.   
     
     
       7. A spring forming apparatus according to claim 2, wherein: each of the plurality of movement converting mechanisms comprises a cam, a cam follower which is always kept in contact with a cam profile of the cam, and a swing arm which carries the cam follower and pivotally moves around a pivot whereby each of the slider assemblies move between the advanced position and the retreated position generally perpendicularly to the axis of the quill in accordance with movement of the swing arm.   
     
     
       8. A spring forming apparatus according to claim 2, wherein: the tool rotating driving mechanism comprises a driving motor, a second large gear which is driven by the tool rotating driving motor, at least one second small gear which is arranged in engagement with a circumference of the second large gear and each corresponding to a working tool holder, and at least one rotational movement axially rotating mechanism by which the rotational movement of the second small gear rotates the working tool holder and the working tool,   the driving motor for the tool rotating driving mechanism being able to be controlled in terms of a rotational speed and a rotational angle.   
     
     
       9. A spring forming apparatus according to claim 2, wherein: at least one of the working tools comprises a wire bending tool which has a pair of projections on an end thereof facing a side of the wire fed through the quill,   the projections having a gap allowing the wire to pass through therebetween, whereby the wire positioned between the pair of projections being bent when the wire bending tool rotates.   
     
     
       10. A spring forming apparatus according to claim 7, wherein: the cam of each of the plurality of the movement converting mechanisms is rotatable within a predetermined angle range of 0° to 360°.   
     
     
       11. A spring forming apparatus according to claim 7, wherein: at least one of the working tools comprises a wire bending tool which has a pair of projections on an end thereof facing a side of the wire fed through the quill,   the projections having a gap allowing the wire to pass through therebetween, whereby the wire positioned between the pair of projections being bent when the wire bending tool rotates.   
     
     
       12. A spring forming apparatus according to claim 4, wherein: at least one rotational movement axially rotating mechanism comprises a bevel drive gear which is rotated by the second small gear, a bevel driven gear which is in engagement with the bevel drive gear, and a rotary shaft which co-axially movably and non-rotatably passes through the bevel driven gear and which is connected to the working tool holder, whereby the working tool holder and the working tool rotate together with the rotary shaft.   
     
     
       13. A spring forming apparatus according to claim 8, wherein: the first common large gear for the slider driving mechanism and the second large gear for the tool rotating driving mechanism are arranged in parallel to each other between the quill and the wire feeding rollers being arranged along the axis of the quill.   
     
     
       14. A spring forming apparatus according to claim 8, wherein: the driving motor for the tool rotating driving mechanism being controlled so as to rotate at least one working tool holder within an angle range of 0° to 360°.   
     
     
       15. A spring forming apparatus according to claim 8, wherein: at least one of the working tools comprises a wire bending tool which has a pair of projections on an end thereof facing a side of the wire fed through the quill,   the projections having a gap allowing the wire to pass through therebetween, whereby the wire positioned between the pair of projections being bent when the wire bending tool rotates.   
     
     
       16. A spring forming apparatus according to claim 12, wherein: at least one of the working tools comprises a wire bending tool which has a pair of projections on an end thereof facing a side of the wire fed through the quill,   the projections having a gap allowing the wire to pass through therebetween, whereby the wire positioned between the pair of projections being bent when the wire bending tool rotates.   
     
     
       17. A spring forming apparatus according to claim 13, wherein: at least ore of the working tools comprises a wire bending tool which has a pair of projections on an end thereof facing a side of the wire fed through the quill,   the projections having a gap allowing the wire to pass through therebetween, whereby the wire positioned between the pair of projections being bent when the wire bending tool rotates.